How can I detect when a file download has completed in ASP.NET?

Question

I have a popup window that displays \"Please wait while your file is being downloaded\". This popup also executes the code below to start the file download. How can I close th

Answer 1

Even though this is an old question it hasn't been answered all this time and I believe it deserves a (better) answer:

https://stackoverflow.com/a/59010319/313935